How to use datepicker utililty function

[said_fox]

Hi,
I have the following input field that I use datepicker to supply it with date:

<input type="text" id="date" name="date" />
<script>
$('#date').datepicker();
</script>

The above code works fine to show calendar and then pick the selected date into the text field.

The problem is: I could not know how to use the utility functions regarded in the documentation of the datepicker for something like formatDate, parseDate, etc.

In the documentation links above they told us to use it as following:

$.datepicker.formatDate('yy-mm-dd', new Date(2007, 1 - 1, 26));
$.datepicker.parseDate('yy-mm-dd', '2007-01-26');

My question is: how could I use the second code with the first code to get my datepicker formated and started with a defined date by me?